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Investments - Maturity Table (Details) - USD ($) $ in Thousands | Sep. 30, 2024 | Dec. 31, 2023
--- | --- | ---
Debt Securities, Available-for-sale [Line Items] |  |
Amortized Cost | $ 2,113,257 | $ 2,563,984
Estimated Fair Value | 2,022,605 | $ 2,411,622
2024 |  |
Debt Securities, Available-for-sale [Line Items] |  |
Amortized Cost | 49,998 |
Estimated Fair Value | 49,922 |
2025 |  |
Debt Securities, Available-for-sale [Line Items] |  |
Amortized Cost | 299,564 |
Estimated Fair Value | 296,634 |
2026 |  |
Debt Securities, Available-for-sale [Line Items] |  |
Amortized Cost | 549,052 |
Estimated Fair Value | 522,070 |
2027 |  |
Debt Securities, Available-for-sale [Line Items] |  |
Amortized Cost | 98,916 |
Estimated Fair Value | 97,582 |
2038 |  |
Debt Securities, Available-for-sale [Line Items] |  |
Amortized Cost | 66 |
Estimated Fair Value | 68 |
2039 |  |
Debt Securities, Available-for-sale [Line Items] |  |
Amortized Cost | 561 |
Estimated Fair Value | 563 |
2042 |  |
Debt Securities, Available-for-sale [Line Items] |  |
Amortized Cost | 2,152 |
Estimated Fair Value | 1,914 |
2043 |  |
Debt Securities, Available-for-sale [Line Items] |  |
Amortized Cost | 3,813 |
Estimated Fair Value | 3,512 |
2044 |  |
Debt Securities, Available-for-sale [Line Items] |  |
Amortized Cost | 4,125 |
Estimated Fair Value | 3,867 |
2045 |  |
Debt Securities, Available-for-sale [Line Items] |  |
Amortized Cost | 4,567 |
Estimated Fair Value | 4,170 |
2046 |  |
Debt Securities, Available-for-sale [Line Items] |  |
Amortized Cost | 7,014 |
Estimated Fair Value | 6,318 |
2047 |  |
Debt Securities, Available-for-sale [Line Items] |  |
Amortized Cost | 6,980 |
Estimated Fair Value | 6,339 |
2048 |  |
Debt Securities, Available-for-sale [Line Items] |  |
Amortized Cost | 1,706 |
Estimated Fair Value | 1,597 |
2049 |  |
Debt Securities, Available-for-sale [Line Items] |  |
Amortized Cost | 14,973 |
Estimated Fair Value | 13,648 |
2050 |  |
Debt Securities, Available-for-sale [Line Items] |  |
Amortized Cost | 102,417 |
Estimated Fair Value | 84,272 |
2051 |  |
Debt Securities, Available-for-sale [Line Items] |  |
Amortized Cost | 146,699 |
Estimated Fair Value | 119,429 |
2052 |  |
Debt Securities, Available-for-sale [Line Items] |  |
Amortized Cost | 59,033 |
Estimated Fair Value | 53,601 |
2053 |  |
Debt Securities, Available-for-sale [Line Items] |  |
Amortized Cost | 312,243 |
Estimated Fair Value | 310,480 |
2054 |  |
Debt Securities, Available-for-sale [Line Items] |  |
Amortized Cost | 132,881 |
Estimated Fair Value | 128,397 |
2055 |  |
Debt Securities, Available-for-sale [Line Items] |  |
Amortized Cost | 75,043 |
Estimated Fair Value | 73,470 |
2056 |  |
Debt Securities, Available-for-sale [Line Items] |  |
Amortized Cost | 200,334 |
Estimated Fair Value | 202,800 |
2058 |  |
Debt Securities, Available-for-sale [Line Items] |  |
Amortized Cost | 41,120 |
Estimated Fair Value | $ 41,952 |

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